Help! About use symsum on matrix

Hello, i am a freshman on matlab

it's a problem about summation of matrix

m=2;

p=[2,3;3,5]; %matrix 2*2

yu=[34;44]; %column vector 2*1

syms t;

rt=symsum((p^t)*yu,t,0,m);

what i want should be the followings:

>> (p^0)*yu+ (p^1)*yu+ (p^2)*yu

ans =

        1600
        2576

however, i get this

>> rt

rt =

 matrix([[102, 102], [102, 204]])
 matrix([[132, 132], [132, 264]])

I don't know why

Please help me

Thanks a lot!

Answer 1

[Andrei Bobrov]

variant without symbolic toolbox

a = arrayfun(@(x)p^x*yu,0:2,'un',0);
rt = sum([a{:}],2)

[zhang]

thank u

urs are right

however, i still want to know how to use symsum to fix it and what is the meaning of "variant without symbolic toolbox" ?

sorry

i do a freshman on matlab

[Andrei Bobrov]

symsum function from Symbolic Math Toolbox (doc symsum)

Your task to solves symsum Maple Toolbox for MATLAB, for its installation, you must have Maple

Answer 2

[Paulo Silva]

Your are missing a dot before the exponent

rt=symsum((p.^t)*yu,t,0,m);

[zhang]

according to ur answer, i got this

>> rt

rt =

278

400

yes, it's has no matrix things, but the answer is not right

it should be like this

>> (p^0)*yu+ (p^1)*yu+ (p^2)*yu

ans =

1600

2576

[Paulo Silva]

I can't find the problem, if you do

syms t p yu

rt=symsum((p.^t)*yu,t,0,m)

you get the same expressions (p^0)*yu+(p^1)*yu+(p^2)*yu

but with p and yu replaced by the array it's not the same, sorry

[Paulo Silva]

also if you choose m=0 it should give yu but it gives [78;78] , 78 is the sum of yu values

[zhang]

maybe i did not express it clear

your suggestion of adding dot before exponent which is another different multiplication operator of matrix

for example

>> A=[1,2;2,3]

A =

1 2

2 3

>> B=A.^2

B =

1 4

4 9

>> C=A^2

C =

5 8

8 13

you see, they are two different operator

[zhang]

Operation Operator Syntax M-Function Equivalent

Matrix power A^B mpower(A,B)

Arraywise power A.^B power(A,B)

you can search word "mpower" in the help

and "Arithmetic Operators + - * / \ ^ '" explain well

thank ur answer